Process of manufacturing electrical conductors.



i Nu.v 709,001. Patgnted sept. l0, |902.

L. w. nowNEs. ER- OCESS'OF MANUFACTURING ELECTBIBAL CNDUCTUBS. n(Application led Feb. 17, 1902.) oooooo el SSSSSSSSSSSS 2 UNITED STATESPATENT EEICE.

LOUIS W. DOWNES, OF PROVIDENCE, RHODE ISLAND.

PROCESS OF MANUFACTURING ELECTRICAL CONDUCLI'QRS.

SPECIFICATION forming part of Letters Patent No. 709,001, datedSeptember 16, 1902. Application filed February 17. 1902. Serial No.94,531. (N0 SPOU111S) To a/Z whom 'it may concern.-

Be it known that I, LOUIS W. DOWNES, a resident of Providence, RhodeIsland, have invented a new and useful Improvement in Processes ofManufacturing Electrical Oonductors, which invention is fully set forthin the following speciiication.

The rapid introduction and use on a large scale of asbestos-insulatedwire has heretofore been prevented by difficulties, first, in producinga ne yarn of this material; second, in reducing the thickness of theinsulation on the wire to such an extent as to enable it to replace thecotton-insulated wire now in use. It must be understood that thespacings allowed for insulation in any electrical apparatus are ofnecessity limited and cannot easily exceed certain reasonableproportions. Any attempt, therefore, to replace existing insulatingmaterial would be extremely difficult unless the new insulating materialemployed possessed the same general dimensions as the old, as anyattempt to discard existing designs and dimensions would unquestionablyfail. Investigators have for many years been seeking a process by whichthe thickness of the insulation where asbestos was employed could bebrought down to reasonable limits. While the inventions of my previouspatents (Nos. 534,785, 534,786, dated February 26, 1895; No. 541,921,dated July 2, 1895, and No. 544,847, dated August 20, 1895) relating toprocesses and machines adapted particularlyfor coating metallicconductors with asbestos insulation have been quite successful inaccomplishing thesev results, extensive experiment and investigationhave disclosed difficulties which have at least tended to retard theindustrial extensionof the use of the asbestos-insulated conductorsproduced according to said in ventions. l These difficulties consist inthe injury done occasionally to the asbestos insulation in the cardingand rolling thereof, particularly in the rolling, as the rolls quitefrequently become clogged and catching the asbestos yarn tear it off theWire. This necessitates stopping the machinery and a material loss oftime in repairing the damaged portion of the insulation. This difficultyis largely due to the fact that the rolls in order to make contact withthe periphery of the covered Wire must be of extremely small diameter,it being necessary to employ three rolls bearing on the wire inpractically peripheral alinement in order to hold the Wire centrally andact uniformly on the asbestos covering.

After extensive experiments I have sncceeded in avoiding thedifficulties above referred to by my present invention,ithe principalfeature of which consists in subjecting` the asbestosinsulation topressure alternately applied and released. This pressure is preferablyapplied in the form of a rapid succession of blows uniformly distributedover the entire surface of the insulation and acting to beat down andcompress the same against the wire, or, in other words, the asbestosinsulation is swaged or subjected to a swaging operation analogous t0that employed in the working of metals. The compressive force beingalternately exerted and released, there is little, if any, danger of thepartsof the mechanism catching and tearing olf the asbestos covering. Atthe same time the covering is compressed, compacted, or felted togetherto a remarkable degree, it being thus possible to reduce the dimensionsof asbestosinsulated conductorsto an equality with and in some instancesactually less than. the dimensions of ordinary magnet-wire insulated,for example, with cotton. I am thus enabled to produce a product ofpractically uniform diameter throughout, greatly improving in thisrespect upon asbestos-insulated conductors produced heretofore.

.The preferred manner of carrying out this invention can best beexplained in connection with the accompanying drawings, wherein- Figures1, 2, 3, and 4 are diagrammatic views of apparatus suitable for thepurpose; and Fig. 5 is a face View, partly in section, of the swagingmechanism, which is the preferred means for intermittently applyingpressure to the insulating-covering and releasing the same.

Referring to Fig. 1, the wire :1; passes from reel A under pulley a,whereby it is carried through gum or other suitable adhesive substancein a pan B. Thence the gnmmed wire passes upwardly througha'suitably--driven Winding apparatusv C, which is similar to that shownand described in my Patent No.

544,847, of August 20, 1895, except that the IOO yarn-bobbins aredisposed horizontally instead of vertically, as in the patent. othersuitable apparatus may of course be employed for applying the asbestosto the conductor. The wire lhaving the asbestos covering applied theretothen passes over the feed-sheave D and down to the reel E. speed atwhich feed-sheave D is driven may be varied according to the speedatvwhich it is desired topass the Wire through t he Winder. Reel E whenfull is removed from its trunnions, Fig. l, and placed in a heatingchamber or oven F, Fig. 2, where the temperature is raised sufiicientlyto cause the adhesive gum on the wire to melt and iirmly engage and fixthe asbestos to the wire. Reel E is then removed from chamber F andplaced on trunnions in'the position shown in Fig. 3. The dry coveredwire then passes from reel E through a suitable napping,r or combingdevice G, which acts to comb or brush out the asbestos covering toremove all superfluous ln inps, irregularities, dac., and lay the napall in one direction. While any suitable device may be employed for thispurpose, that preferred and illustrated is the same as shown in myPatent No. 534,785, of February 2G, 1895. From the napping` device theWire passes under a drip-pipe or spraying device Il, whereby theasbestos covering is thoroughly moistened and brought to suitablecondition for the compression thereof which follows. The conductorcovered with moistened asbestos next passes to the mechanism K, Fig. 3,for com pact/ing the insulation by the intermittent application andrelease of pressure. Whileanysuitable mechanism may be employed for thispurpose, that preferred is analogous to the ordinary swaging mechanismused in metal-working. Suitable mechanism for this purpose is clearlyshown in Fig. 5, wherein K is an annular casing having a series ofhardened-steel-metal rollers 7c projecting from sockets around its inneredge. Lisahub rotated Within casing K through its pulley, Fig. 3. m 'mare slides movable in a recess which extends laterally through hub L. Atits outer end each slide carries hardened-steel roller n, projectingfrom a socket therein. At its inner end each slide carries a die 0 o,having a semicircular recess in its face. As the hub L is rotated therollers n strike the rollers 7c, causing the dies in a Well-known mannerto impart a rapid succession of blows to the insulating-covering on theconductor, with the effect already explained. From the mechanism K, Fig.3, the covered wire passes over a feed-sheave P, which acts to draw thewire from reel E through the napping and swaging devices. Upon leaving,rthe sheave P the Wire is wound on reel M. After allowing the coveredWire thereon to thoroughly dry out the reel M is placed on trunnions, asshown in Fig. 4, and the covered Wire passed therefrom under pulleys r rthrough a suitable finishing solution-such as japan, for example--in atank R. A steam-coil or other heat- `Any,

The

ing means is employed to keep the solution in a heated state, so that itwillthoroughly' penetrate the insulating-covering on the Wire. Uponemerging from the solution in the tank the covered wire passes through aWiper S,

Vwhich removes superiiuous finishing solution taken up by the wire. Thewire is finally wound on a reel T. It may then be dried by artificialheat and isready for the market.

Whilell have described above the preferred manner and mechanism forcarrying out my invention, it. may of course be practiced in manyotherways. The insulating-covering may be applied to the conductor inany Silitable form and manner and the rapid intermittent application andrelease of pressure effected by any suitable means. It may be founddesirable in some cases to entirely omit one or more of the steps as,for example, the napping. Fu rtherinore,wl1ile the process isparticularly adapted to the production of conductors insulated withasbestos it may also be used to advantage in making conductors insulatedwith other materials. It is therefore apparent that modifications may bemade within wide limits without departing from the nature and principleof the invention.

What I claim isl. vThe herein-described process of producing insulatedelectrical conductors consisting in covering the conductor with asuitable insulating material and subjecting the insulation to pressurealternately applied and released, thcreby compacting the insulation onthe conductor.

2. The herein-described process of producing insulated electricalconductors consisting in covering the conductor with a suitableinsulating material and subjecting the insulation to pressurealternately applied and released in rapid succession, thereby compactingthe insulation on the conductor.

3. The herein-described process of producing insulated electricalconductors consisting in covering the conductor with a suitableinsulating material and subjecting the insulation to pressurealternately applied and re.- leased in rapid succession, the applicationof the pressure being equally distributed over the entire surface of theinsulation, thereby uniformly compacting the insulation on theconductor.

4. T he process of producing electrical conductors consisting incovering a conductor With a suitable insulating material, and subjectingthe covered conductor to a rapid succession of blows uniformlydistributed over its surface.

5. The process of producing electrical conductors consisting in coveringa conductor with a suitable insulating material, and swaging the coveredconductor thereby compacting the insulation.

6. The process of producing insulated electrical conductors consistingin applying an adhesive substance to a conductor, covering IOO IIC

IZO

the conductor with a suitable insulating inaterial, and subjecting thecovered conductor to pressure alternately applied and released in rapidsuccession, therebycompacting the insulation ou the conductor. y

7. The process of produoin"r insulated electrical conductors consistingin applyingan adhesive substance tota conductor, covering t rs theconductor with asuitable insulating material, heating the coveredconductor to a temperature sufficient to melt the adhesive substance andsubjecting the covered conductor to pressure alternately applied andreleasedin rapid succession thereby compactiner the insnlationjon theconductor.

y t 8. The processof producing insulated electrical conductorsconsisting in applying an adhesive substance to a conductor, covering ythe conductor with a suitableinsulating material, napping theinsulatilig-coveringT to re.- move irregularities and lay the nap all inone direction and subjecting the covered conductor to pressurealternately applied and released in rapid succession thereby compact.-ing the insulation on the conductor.

9. The process of producing insulated electrieal conductors consistingin covering the substance, napping the insulating-covering to removeirregularities and lay the nap all in the saine direction, moisteningthe insulating-covering and subjecting the covered couductor to pressurealternately applied and released in rapid succession thereby compactingrthe insulation ou the conductor.

In testimony whereof I have signed this specification in the presence oftwo subseribing Witnesses. y

LOUIS lV. DOWNES.

VVitnes'ses: f

JAMES II. THURsToN, EDWIN P. ALLEN.

